1、Designation: D4724 10Standard Test Method forEntanglements in Untwisted Filament Yarns by NeedleInsertion1This standard is issued under the fixed designation D4724; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers two options for the measure-ment of entanglements in untwisted filament yarns usingneedle insertion
3、options for instrument (A) and manual (B)techniques.1.2 The values stated in either SI or inch-pound units (inparentheses) are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system must be used independently of the otherwithout com
4、bining values in any way.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations pri
5、or to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD2258 Practice for Sampling Yarn for Testing3. Terminology3.1 Definitions:3.1.1 entanglement, nthe extent or degree to which thefilaments in a yarn are interl
6、ocked and cannot be readilyseparated.3.1.1.1 DiscussionThere are two kinds of entanglements,intermediary (loose) node and hard (tight) node. Intermediarynodes are pulled out easily under tension or separated by aneedle. This test method is a measure of the presence of hardnodes in which the interloc
7、king or interlacing is compactpulling the yarn bundle together.3.1.2 filament yarn, na yarn composed of (continuous)filaments assembled with or without twist.3.2 For definitions of other textile terms used in this testmethod, refer to Terminology D123.4. Summary of Test Method4.1 A summary of each o
8、ption is in the section for thatoption.5. Significance and Use5.1 Option 1 of this test method for the determination of thedegree of untwisted filament yarn entanglement, as measuredinstrumentally, is used for acceptance testing of commercialshipments; however, caution is advised because information
9、 onbetween-laboratory precision is lacking. Comparative tests, asdirected in 5.1.1, may be advisable.5.1.1 If there are differences of practical significance be-tween the reported test results for two or more laboratories,comparative tests should be performed by those laboratories todetermine if the
10、re is a statistical bias between them, usingcompetent statistical assistance. As a minimum, samples usedfor each comparative test should be as homogeneous aspossible, drawn from the same lot of material as the samplesthat results in disparate results during initial testing, andrandomly assigned in e
11、qual numbers to each laboratory. Otherfabrics with established test values may be used for thispurpose. The test results from the laboratories involved shouldbe compared appropriate statistical analysis and a probabilitylevel chosen by the two parties before testing begins, at aprobability level cho
12、sen prior to the testing series. If a bias isfound, either its cause must be found and corrected or futuretest results must be adjusted in consideration of the knownbias.5.2 Option 2 for this test method is intended for use whenthe supply of yarn is limited.5.3 The instrumental option of this test m
13、ethod is based onthe total randomization of the entanglements in the yarn;therefore, the distance measured between the point of insertionof a pin in the middle of the yarn and the point at which an1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsi
14、bility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved Aug. 1, 2010. Published September 2010. Originallyapproved in 1999. Last previous edition approved in 2009 as D472409. DOI:10.1520/D4724-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
15、Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.entanglement is encountered, by
16、 movement of the yarn or thepin until it is stopped at a preset level of force, is representativeof the distance between two entanglements at some location inthe yarn.5.4 Entanglements are used frequently instead of twist toensure the integrity of filament yarns. Such entanglementsgenerally give som
17、ewhat less protection during weaving orknitting than twist, but with proper care, will perform quitesatisfactorily.6. Sampling and Test Specimens6.1 Primary Sampling UnitConsider shipping containersof yarn to be the primary sampling unit.NOTE 1A realistic specification or other agreement between the
18、purchaser and the supplier requires taking into account the variabilitybetween shipping containers, packages within a shipping container, andsuccessive lengths from a package to provide a plan that, at the specifiedlevel for the property of interest, has a meaningful producers risk,consumers risk, a
19、cceptable quality level, and limiting quality level.6.2 Laboratory Sample UnitFor each primary samplingunit, take laboratory sampling units as directed in PracticeD2258. Do not rewind or transfer material from packages takenfrom shipping containers to another packages.6.3 Test SpecimenFor acceptance
20、 testing, use laboratoryunits as a source of specimens. Make 20 observations on eachlaboratory sampling unit.7. Conditioning7.1 Preparation of Test PackageBefore preconditioningor conditioning the test package, remove at least 100 m or 110yds of yarn from the test package to avoid testing nonrepre-s
21、entative yarn.7.2 PreconditioningNormally, preconditioning is not nec-essary unless the test packages are received with higher thanthe normal moisture level. If preconditioning is necessary, treatthe packages as directed in Practice D1776.7.3 ConditioningCondition the test packages as directedin Pra
22、ctice D1776.OPTION 1INSTRUMENTAL MEASUREMENT OFTHE DEGREE OF ENTANGLEMENT OFUNTWISTED FILAMENT YARN8. Summary of Option8.1 A yarn is passed at constant speed and constant preten-sion through the thread path of the instrument. After a requiredyarn length has run through, the yarn is pierced by a need
23、le,and advanced automatically until a preset needle tension isattained. Then, the needle is withdrawn, and the yarn lengthfrom insertion to this critical point is measured automatically.This cycle of yarn advance, piercing by the needle, and lengthmeasurement is repeated for a predetermined number o
24、f times.The individual measured pulled yarn lengths and the total ofthese yarn lengths are automatically recorded.9. Apparatus9.1 Automatic Needle Pull Entanglement Testers, rapidautomatic pin insertion detector (RAPID)3and Rothschildautomatic yarn entanglement testers NPT.39.2 Standard Laboratory W
25、eights, ranging from 1 to 100 g.9.3 Stopwatch, with15-s divisions.9.4 Speed Indicator, tachometer, 0 to 1000 rpm range.9.5 Magnetic Whorl Tensioning Device, optional.10. Procedure10.1 Test the yarn in the standard atmosphere for testingtextiles, as directed in Practice D1776.10.2 Calibrate the entan
26、glement tester and tensiometer asprescribed by the instrument manufacturer.10.3 Mount the test package on a suitable holder.10.4 Yarn PretensionCalculate the pretension by usingone of the equations below:YP g!5D 0.5! 0.75 (1)YP cN!5T 0.5! * 0.70 (2)10.5 Trip Level TensionCalculate the trip level by
27、usingone of the equations below:TLTg!5D 0.35! * 3.5 (3)TLT cN!5T 0.35! * 3.31 (4)where:YP = Yarn pretension,TLT = trip level tension, c/tex (gf/d),T = linear density, tex,D = linear density, denier, andF = filament count.10.6 Set the RAPID instrument as follows:10.6.1 Measuring Speed1020 m/min.10.6.
28、2 Observations/Package20.10.6.3 No-Show LengthRefer to the manufacturersmanual.10.6.4 Present the loose end of the yarn to the inlet gun (seeFig. 1). The instrument will string up, automatically strip someyarn, start the measurement cycle, and discard the tested yarnto waste.10.6.4.1 If there is no
29、entanglement in the “No-Show”length, the instrument will do the following:(1) If the “Pin Miss Ignored Limit” has not been exceeded,rotate the pinwheel, reinsert the needle in the yarn, andcontinue testing. The test is aborted and a “No-Show” re-corded.(2) If the “Pin Miss Ignored Limit” has been ex
30、ceeded, entera “Freeze” state and request confirmation of pin insertion. Theoperator will restart the test if the pin did not pierce the yarn(increasing the “Pin Miss Count” by 1, or the operator willacknowledge pin piercing by pressing the “Confirm” buttondesignating this a true no entanglement sec
31、tion, which adds thelength to the results.10.7 Set the Rothschild instrument as follows:10.7.1 Measuring Speed1020 m/min.10.7.2 Forwarding Time5 s.3Apparatus is commercially available.D4724 10210.7.3 Observations/Package (decade counter)20.10.7.4 No-Show Length500 mm or as specified by user.This is
32、an optional setting and the length should be establishedbased on the product or end-use of the product.10.7.5 Feed the yarn from the package through the preten-sion device. The yarn then is threaded across the needlepiercing section and through the measuring head. Then, yarngoes to a yarn speed roll
33、 and is taken up to the “Take-up” wheel(see Fig. 2) or can bypass the “Take-up” wheel and go into theaspirator after the yarn speed roll, to prevent buildup on thetake-up wheel. The software initializes a specified length forstripping and starts the test.10.7.5.1 If there is no entanglement in the “
34、No-Show”length, the instrument will do the following:(1) Stop the yarn and withdraw the needle.(2) Record a “No-Show” in the software (and on theprintout).(3) Reinsert the needle into the yarn and wind until a node(entanglement) is detected.(4) The first entanglement after a “No-Show” is ignored.(5)
35、 The needle is withdrawn, and the yarn is advanced thespecified length of the entanglement and is reinserted into theyarn and the test continues. This is to ensure that an accuratereference between entanglement is established.10.7.6 Remove the yarn from the take-up wheel frequentlyto avoid excessive
36、 waste build-up. Use care if a sharp blade isused. To avoid any build-up, the yarn may be placed in theaspirator after the last wrap on the “Yarn speed roll.”11. Calculations11.1 In the following way the tester computer will calculatethe average number of entanglements per metre using:The total coun
37、t of entanglements measured must equal 100.FIG. 1 Yarn String-Up Diagram for Rapid Automatic Pin Insertion Detector (RAPID)FIG. 2 Yarn String-Up Diagram for Rothschild Needle Insertion Entanglement ApparatusD4724 103The Distances between Entanglements (DE) must be re-corded individually.The average
38、Distance between Entanglements (DEavg)iscalculated using Eq 5:DEavg5(i 51100DEi100(5)The standard deviation in this average value is calculatedusing Eq 6:DEstdev5(i 5 1100DEi DEavg!299(6)The average number of entanglements per meter (EPM) iscalculated using Eq 7:EPM 51DEavg(7)The standard deviation
39、in the average number of entangle-ments is calculated using Eq 8:EPMstdev5DEstdevDEavg!2(8)The half length of the 95% confidence interval (CI95) iscalculated using Eq 9:C195 5 t2=n 0.2 s (9)where:DE = Distance between Entaglements, andEPM = average number of entanglements/m.11.2 Calculate the averag
40、e entanglements/m for the lot.12. Report12.1 State that the packages were tested as directed inOption 1 of Test Method D4724. Describe the material orproduct sampled and the method of sampling used.12.2 The report shall include the following information:12.2.1 Nominal linear density.12.2.2 Pretensio
41、n level used.12.2.3 Trip level tension used.12.2.4 Measuring speed.12.2.5 Transport time.12.2.6 The distances between entanglements for each speci-men.12.2.7 No show distance and any no shows encountered foreach specimen.12.2.8 The EMC for each package and the average for thelot.12.2.9 The instrumen
42、t used.12.2.10 Any modifications to the test.OPTION 2MANUAL MEASUREMENT OF DEGREEOF FILAMENT ENTANGLEMENT13. Summary of Option13.1 A stationary needle is inserted in the yarn. A hook isplaced in the same opening made by the needle. The hook isattached to one end of a flexible cord and a tensioning w
43、eightto the other end of the cord. The weight is allowed to dropvertically and gradually until the hook is stopped by anentanglement in the yarn. The needle is then moved in theopposite direction along the length of the specimen until itencounters another entanglement. The distance between thehook a
44、nd needle is recorded as the distance between entangle-ments. See Fig. 3.14. Apparatus14.1 Weight, 2.5 6 0.01 g.14.2 J-Shaped Hook, approximately 25 mm long.14.3 Cord, or thread, flexible, No. 50 cotton.14.4 Illuminated Magnifier3, with a lens capable of 3x to10x magnifications.14.5 Horizontal Test
45、Board, equipped with a sliding metricscale, movable black plastic perforated card 25 by 75 by 1.6mm (1.0 by 3.0 by116 in.), and yarn clamp.14.6 Air Jet Suction.14.7 Pick Needle.14.8 Tensiometer.15. Procedure15.1 Test the yarn in the standard atmosphere for testingtextiles, as directed in Practice D1
46、776.15.2 Place the yarn package on a suitable stand under thetable supporting the test apparatus.15.3 Feed the yarn through the test apparatus.15.4 Open the main air valve completely for the air jetsuction device and strip off the outside layer of yarn.15.5 Attach the J-hook to one end of the cord,
47、or thread, andfeed the other end through the guide at the left side of the testboard. Cut the cord to a length that allows it to hang at least750 mm above the floor. Attach the weight to the free end ofthe cord.15.6 Adjust tension on the yarn to 0.1 cN (0.01 gf/d) usinga valve at the air jet. Do thi
48、s while the air jet is pulling againstthe yarn that is held stationary by a clamp on the right side ofthe test board.15.7 Place the magnifier over the control test area.15.8 Slide the plastic card under the yarn.15.9 Push the pick needle through the center of the yarn andmake an opening wide enough
49、for the J-hook. Extend the pickneedle into a hole in the card.15.10 Insert the hook into the opening next to the pickneedle and let the hook move gently to the left until it catcheson an entanglement (hard node) and its mass holds it in theyarn.15.11 With the pick needle still in the yarn, pull it from thecard and gently move it to the right until resistance due toanother entanglement (hard node) is encountered.15.12 Move the card out of the way, measure the distancebetween the hook, and pick needle (two entanglements) to theneare
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1